Owners of vehicles with a cargo area (such as pickup truck) often purchase a cargo cover in order to protect and secure the cargo situated within the cargo area. There are of course many types of cargo covers available to pick-up truck owners, such as flat cargo covers and box type cargo covers. A flat cargo cover is relatively flat in shape and when in the closed position lies substantially planar upon the side rails of the pick-up truck cargo areas and provides coverage to the entire cargo area. Due to its flat shape, it is relatively easy to attach the flat cargo cover to the cargo area by providing a standard hinge positioned at the front (the portion near the passenger cab) of the cargo area. A flat cargo cover typically does not increase the secured cargo area of a pick-up truck when in the closed position. Thus, there are often times when a flat cargo cover does not provide enough secured area to carry the desired volume of cargo. In comparison, while in the opened position a flat cargo cover does provide greater access to the cargo area and also allows the user to carry more cargo in an unsecured manner by allowing cargo to exceed the height of the cargo area side walls.
For at least the above reasons, many times a pick-up truck owner will not select a flat cargo cover and will instead employ a box type cover since it provides additional secured cargo space. One drawback to a box type cargo cover is that it is impossible to open and close in the same manner as a flat cargo cover (with a simple hinge as described above) due to the height of the rear wall of the pick-up passenger cab and the height of the front wall of the box cargo cover. Utilizing a simple hinge at the lower front base of the box type cargo cover would cause the rear wall of the pick-up passenger cab and the front wall of the cargo cover to contact each other when attempting to open the cargo cover. This contact would prohibit any upward pivoting motion of the box cargo cover in relation to the cargo area. Therefore, users of typical box cargo covers have been limited to the height of the cargo they can carry within the cargo area. Instead of tilting the box cargo cover, users were relegated to accessing the cargo area through a door located at the rear of the box cargo cover.
To that end, numerous systems are known which provide various mechanisms for lifting various types of box cargo covers.
One such known device is that set forth in U.S. Pat. No. 5,102,185 to Lake, issued Apr. 7, 1992. The Lake device teaches a lifting cargo cover which utilizes an inner structure mounted within the cargo area to act as support for the tilt mechanism of the cargo cover. This design is comprised of a separate front wall portion which is hinged at its top to the remaining portions of the cargo cover. This separated design creates the potential for leaks into the cargo area as well as increased wind noise while in transit. This design requires an inner standalone structure which occupies valuable cargo area floor space. In order to utilize this design a purpose built box cargo cover would need to be constructed. In other words, this design could not be easily retrofitted to a standard box cargo cover.
Another known device is that set forth in U.S. Pat. No. 5,104,275 to Enninga, issued Apr. 14, 1992. This device solves one of the perceived shortcomings of the Lake device which necessitated that the box cargo cover be built in separate pieces. By moving the lift/support structure rearward in relation to the truck cab, the Enninga device relocated the swivel/lift point to an area further away from the truck cab thereby allowing the box cargo cover to lift and pivot in relation to the cargo area of the pick-up. This improvement allowed the box cargo cover to be built as a unitary structure, meaning that the front and sides of the cover are all fixedly attached. Although this was an improvement over the Lake device, the Enninga device, similar to the Lake device, still required a separate structure to be placed at least partially upon the cargo area floor, there taking up cargo space otherwise available for hauling cargo. Like the Lake device, in order to utilize this design a purpose built box cargo cover would need to be constructed. In other words, this design could not be easily retrofitted to a standard box cargo cover.
Yet another device set forth in U.S. Pat. No. 5,595,418 to Medlin, issued Jan. 21, 1997, teaches a lift mechanism which improves upon both Lake and Enninga in that the Medlin device does not require a standalone support unit upon the floor of the cargo space area. This device utilizes the front wall (closest in proximity to the pick-up truck cab) for supporting and mounting the lift mechanism. Although this design does solve the perceived shortcomings of both Lake and Enninga, use of the Medlin device still requires the construction of a purpose built box cargo cover in order to support the lift mechanism. Similar to the Lake and Enninga devices, this design also could not be easily retrofitted to a standard box cargo cover.
Later came the device set forth in U.S. Pat. No. 6,543,834 to Sisson, issued Apr. 8, 2003. Although the working of the actual lift mechanism of the Sisson device is somewhat different than that set forth in the Lake device, the structure and basic function of the Sisson device incorporates the same shortcomings as set forth above for the Lake device.
The last relevant device is set forth in U.S. Pat. No. 7,275,779 to Hebron, issued Oct. 2, 2007. In order to remove the inner support structure from the cargo floor area as required by the Lake, Sisson, and Enninga devices, this device relocated the lift mechanism to the wheel well area. This device lifts the box cargo cover from the side in a manner which tilts the box topper on its side when opened. This device utilizes a single lifting mechanism mounted upon the wheel well of the cargo area. Although this device does provide a bit more usable cargo area that the previously mentioned devices, this device does occupy some cargo space and was not designed for transporting cargo with the box cargo cover in the opened or partially opened position. When opened, this cargo box cover hangs off of the side of the vehicle and perhaps into traffic or roadside objects. Is also doubtful that this device would be structurally sound enough to travel in the opened position.
Therefore, it would be desirable in the art to construct a box cargo cover lift mechanism which: a) does not require a purpose built cargo cover thereby reducing the cost of implementing such a lift device, b) is constructed in a manner that can be retrofitted to a standard pre-existing box cargo cover, c) is constructed in a manner that does not require a separate support member mounted in the floor or wheel well spaces of the cargo area, d) is designed to safely allow the transportation of cargo while the box cargo cover is in the opened position, and e) is designed and constructed in a manner which makes it universally adaptable to existing pick up truck cargo areas.
Accordingly, the present invention overcomes the aforementioned shortcomings of the known prior art and provides improvements as stated above. The present invention is summarized and described in detail below.